CA1269741A - Measurement of engineering components - Google Patents
Measurement of engineering componentsInfo
- Publication number
- CA1269741A CA1269741A CA000504566A CA504566A CA1269741A CA 1269741 A CA1269741 A CA 1269741A CA 000504566 A CA000504566 A CA 000504566A CA 504566 A CA504566 A CA 504566A CA 1269741 A CA1269741 A CA 1269741A
- Authority
- CA
- Canada
- Prior art keywords
- component
- computer
- probe
- data
- gauging
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/42—Recording and playback systems, i.e. in which the programme is recorded from a cycle of operations, e.g. the cycle of operations being manually controlled, after which this record is played back on the same machine
- G05B19/4202—Recording and playback systems, i.e. in which the programme is recorded from a cycle of operations, e.g. the cycle of operations being manually controlled, after which this record is played back on the same machine preparation of the programme medium using a drawing, a model
- G05B19/4207—Recording and playback systems, i.e. in which the programme is recorded from a cycle of operations, e.g. the cycle of operations being manually controlled, after which this record is played back on the same machine preparation of the programme medium using a drawing, a model in which a model is traced or scanned and corresponding data recorded
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/18—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form
- G05B19/401—Numerical control [NC], i.e. automatically operating machines, in particular machine tools, e.g. in a manufacturing environment, so as to execute positioning, movement or co-ordinated operations by means of programme data in numerical form characterised by control arrangements for measuring, e.g. calibration and initialisation, measuring workpiece for machining purposes
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/36—Nc in input of data, input key till input tape
- G05B2219/36523—Select with code on workpiece, fixture, clamp, object
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37075—Print out of document measured results or record on tape
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37194—Probe work, calculate shape independent of position, orientation, best fit
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37196—Measuring station, flexible, integrated cmm
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37574—In-process, in cycle, machine part, measure part, machine same part
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/37—Measurements
- G05B2219/37617—Tolerance of form, shape or position
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/50—Machine tool, machine tool null till machine tool work handling
- G05B2219/50063—Probe, measure, verify workpiece, feedback measured values
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/50—Machine tool, machine tool null till machine tool work handling
- G05B2219/50358—Work handling, automatic load unload workpiece
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/50—Machine tool, machine tool null till machine tool work handling
- G05B2219/50391—Robot
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B2219/00—Program-control systems
- G05B2219/30—Nc systems
- G05B2219/50—Machine tool, machine tool null till machine tool work handling
- G05B2219/50399—Between machines
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Human Computer Interaction (AREA)
- Manufacturing & Machinery (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
Abstract
ABSTRACT
IMPROVEMENTS IN OR RELATING TO THE MEASUREMENT
OF ENGINEERING COMPONENTS
A method and apparatus are described for the automatic gauging of engineering components. The apparatus includes clamp means for holding a component to be gauged; probe means for scanning a surface of the component; drive means to provide relative motion between the component and the probe means in three mutually perpendicular axes; measuring transducer means associated with the drive means and the probe means to generate signals to measure the degree of movement between the component and the probe means; computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve; computer means for comparing signals generated by the measuring transducer means with the corresponding singals in the memory means; computer means for calculating the error between the stored data and signals generated by the measuring transducer means to stack the component to maximise desired coincidence between the dimensions of the reference profile and the actual component.
The method and apparatus are described with reference to the gauging of components having aerofoils.
IMPROVEMENTS IN OR RELATING TO THE MEASUREMENT
OF ENGINEERING COMPONENTS
A method and apparatus are described for the automatic gauging of engineering components. The apparatus includes clamp means for holding a component to be gauged; probe means for scanning a surface of the component; drive means to provide relative motion between the component and the probe means in three mutually perpendicular axes; measuring transducer means associated with the drive means and the probe means to generate signals to measure the degree of movement between the component and the probe means; computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve; computer means for comparing signals generated by the measuring transducer means with the corresponding singals in the memory means; computer means for calculating the error between the stored data and signals generated by the measuring transducer means to stack the component to maximise desired coincidence between the dimensions of the reference profile and the actual component.
The method and apparatus are described with reference to the gauging of components having aerofoils.
Description
i9~
~MPROVEMENTS IN OR RELATING TO THE MEASURE~ENT
OF EnGINEERING COMPONENTS
The pr~sent invention relates to the gauging and machining of engineering components having complex curved shapes and particularly to the gauging and machining of components having aerofoil sections such as, for example, blades and nozzle guide vanes for gas and steam turbine engines and compressors.
When a component hav;ng an aerofoil section ;s produced by mach;ning, forging or casting tech-ni~ues, it ;s usually necessary to perform a measuring operation on the component to ensure that it lies within the allowable tolerances pertain;ng to that IS part;cular component. The aerofo;l ;tself often has to sat;sfy tolerances not only on d;mens;ons or thickness relating to a nominal aerofoil profile wh;ch it is des;red to ach;eve at any g;ven sect;on, but also on the actual shape of the sect;on where local areas may have to be constrained within a narrow-er shape tolerance band. Effectively the surface pro~;le oi a chordal sect;on of the aerofo;l must l;e as a whole w1th;n a th;ckness tolerance band whilst each sur~ace of the profile must lie within a narrower shape tolerance band. The shape tolerance band~ however, may be at any position within the th;ckness tolerance band.
~9I~
~, , .... ...~
..
...... ..
~697~
Presently, methods of carrying out these aerofoil measurements largely depend upon how many of the particular component have to be checked. Where the - component in question is a long-run item of which S many repeat batches are likely to be made with total numbers running into thousands~ the preferred method ;s a device known as a multi-point probe. Such devices have, as the;r name suggests, multiple probes wh;ch contact the aerofoil at many points around several sect;ons s;multaneously and compare those sections w;th standard master aerofo;ls on wh;ch the dev;ce has been cal;brated. The ;nformat;on generated ;s usually d;splayed or recorded ;n d;g;tal form on modern vers;ons of the machine and from the information appropriate reci~ication by machining, etc., of the component May be carr;ed out if necessary. Mult;-po;nt probes are very expens;ve and each probe ;s l;m;ted to gauging a s;ngle des;gn of component.
Mult;-point probes are best su;ted to components hav;ng a mult;pl;c;ty of planar ~1.e. non-curved) features and they are used on curved surfaces usually only in those instances where other checks ln the manufacturing process, for example, have g;ven conf;-dence ;n the capab;lity to hold localised shape varia-t;ons ;n controlc Multi-po~nt probes only check the d;menslon at the actual point contacted by the probe itself; ;t cannot guarantee that the slope ., ' .... .. .. .
, ,,"'' ~ "' .
, ~ ~
. .
or d;mension between the contact points is within tolerance~ hence the need for confidence in the manu-~acturing process. The production of multi-point gauges having a sufficiently high resolution to check on shape would require extremely expensive tool;ng.
It is not certain, however, that such gauges would be able to achieve a sufficiently close spacing of the probe array~
At the other end of the scale where only a rela-~;veLy small number of components are envisaged, the methods of aerofoil gauging tend to be more rud;-mentary. Even rud;mentary methods, however, are frequently used in volume product;on. Mechanical comparator gauges are often used where a blank corres-ponding to the des;red aerofo;l shape is clamped;n the device on one side and the component to be checked on the other side. A jockey wheel ~ollows the blank at a chosen sect;on and the probe of a dial gauge follows a corresponding section of the 20 component. The gauge operator observes the dev;at;on of the component from the des;red section and marks up the aerofo;l w;th, for example, an appropriate colour code for subsequent mach;n;ng. Most mach;n;ng ;s carr;ed out by abrasive belt gr;nd;ng. Once the 2S operator has taken action to remove excess metal at a part;cular section, the component has to be ~&j9~7'~1 replaced in the gauge to check whether the action has been adequate~ Even w;th an expensive multi-po;nt probe it is still necessary for the blade to be manually rectified and subsequently re-checked.
S Thus, existing processes for the gauging and nachining of aerofoil components are extremely labour-;ntensive and susceptible to mistakes on the part of the operator.
In between the two extremes of mechanical gauging there are devices known as optical measuring machines or projectors typified by the OMT type of machine.
In th;s method, the component ;s clamped in a fi~ture and the desired aerofo;l sect;on is followed by a roller or stylus wh;ch ;s l;nked to a grat;cule having concentric c;rcles represent;ng var;ous tolerance bands~ A magn;fied ;mage (often X10) of the grat;cule ;s d;splayed on a screen in front of the operator.
A transparent film on wh;ch ;s drawn an acurate prof;le of the des;red aerofo;l, scaled up by a factor equal to the magn;ficat;on be;ng used, ;s placed on the operator's screen so that the image of the concentric c;rcles ;s super;mposed upon the prof;le. The operator follows the actual aerofo;l sect;on on the component with the roller or stylus and s;multaneously views the screen to observe how the grat;cule image wh;ch is follow~ng the component also follows the prof;le of the des;red aerofo;l on the screen. Depend;ng :. .
' :i' . ,: . , , . .
. ~. . .
~ 7~
on wh;ch of the tolerance bands in the grat;cule image coincides with the desired aerofoil profile image will determine whether the blade is in or ou~
o~ ~olerance. The aerofoil may have either excess metal at a particular posit;on or be unders;ze corres-ponding to a metal-on or a metal-off condition~ respect-ivelyu Clearly, ;f a component aerofoil is gauged in a fixed orientation and posit;on w;th reference to a desired aerofo;l also in a fixed orientation and pos;t;on and a metal-off cond;tion perta;ns and the aerofoil is outs;de tolerance ;n that cond;tion, then there is little that can be done in most instances to replace m;ssing metal and the component may, there-fore, be scrap. The actual aerofoil profile itselfmay be within tolerance with regard to both thickness and shape its position in space, however, ~ith respect to same datum such as, for example~ the blade root may be outs;de tolerance. Such pos;t;onal errors of the whole aerofo;l may be compensated for by what are known as stack;ng tolerances~ The whole actual and reference aerofo;ls may be moved relat~ve to each other to ach;eve a best-f;t condlt;on between the two prof;les. The sh;ft requ;red to ach;eve that best-f;t ;s the stacking. Whether or not the component is then with;n tolerance w;ll depend upon the àctual d;mens;onal stack;ng sh;ft made relat;ve 74~
to the stack;ng tolerance allowable on the spec;fic component. Such stack;ng sh;fts may compr;se ;n ~he plane of the aerofoil two linear shifts ;n mutually perpend;cular d;rections plus rotation. Stacklng is, therefore, appl;ed ;n an attempt to br;ng the actual component surface w;thin both the dimensional or thickness and shape tolerances referred to above~
The operator of an OMT-type mach;ne may, therefore, adjust the pos;t;on of the reference aerofo;l with;n an allowable stack;ng tolerance to ach;eve a "best-f;t"~ Thus, the degree of metal-on and metal-off cond;t;ons may be adjusted such that a m;n;mum of metal from a metal-on pos;t;on, ideally on the low pressure surface, has to be removed to br;ng the whole aerofoil sect;on within the requ;red tolerances.
The method still thus necess;tates a high level of operator skill in that he needs to follow the graticule image at all t;mes and must assess the degree of stacking required by a manual ;terative process prior to any actual machin~ng being undertaken on the com-ponent, usually by another operator~ After machinlng, the component aga;n needs to be checked.
Clearly, where mechan;cal comparator gauges are employed and both component and reference blank are in f;xed orientat;on and pos;t;on there ;s no scope whatever for any stack;ng operat;on to be carr;ed out by the operator.
. ,, .. ~ :- -: , . -.,.. ,, ,, , :
....
: .: ., . ,, ",.
74~
In the case of optical measur;ng mach;nes the term "best-fit" used above is not an absolute des-cr;ption but a relative term only. Where the operator has to manually adjust the relat;ve posit;ons of the component and desired aerofo;ls he can only apply, in effect, s;mpl;fied visual criter;a to the operat;on and thus the applied visual "best-fit" w;ll only be the result of the projector operator's judgement.
Such iudgement may vary from operator to operator and also from day to day in the same operator~ The ex;sting methods of applying stack;ng shifts have necessarily been s;mple as heretofore the fac;l;ties to compute the opt;mum stack;ng ;n a machine have been unava;lable.
It is an object of the present invention to prov;de means ~or the gauging of aerofoils which do not rely on expens;ve, dedicated, multi-po;nt probes. It is a further object to provide means for such yaug1ng which are less labour-intensive and require less operator sk;ll than opt;cal measuring machines and mechan;cal comparator gauges.
It ;s a yet further object of the present in-vent;on to provide, in add;t10n to the gauging means stated above, means for the automat;c rectification by machining o~ components~
, , ' .
. ~
.:. . :
:, ; ,.............. ...
-...................... ~ '.; ~ , :. ~ .
7'~
According to a first aspect of the present invent-;on, a method for the automatic gauging of engineering components includes the steps of:
producing relative movement by dr;ve means between the component and probe means in two axes;
scanning the component surface with the probe means by means of a computer prOgraM controlling the relat;ve movement;
generat;ng s.;gnals relating to component dimen-s;ons and geometry by transducer means associated with the relative movement between the component and the probe means;
compar;ng by computer means the generated signals with data stored ;n computer memory means and which relates to a reference prof;le wh;ch it ;s desired to ach;eve;
calculat;ng the error by computer means between the generated,s;gnals and the stored data;
stacking the measured component data by computer means to ach;eve an acceptable degree of co;nc;dence between the reference prof~le and the actual component profile.
According to a second aspect of the present lnvention, apparatus for gauging of turbine components ~5 comprises:
. .
:.. . ::: , :
.. , ~.".
74~
clamp means for holding a component to be gauged;
probe means for scanning a surface of the component;
dr;ve means to provide relative motion between the component and the probe means in three axes;
measuring transducer means associated with the drive means and the probe means to generate signals to measure the degree of movement between the component and the probe means;
computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve;
computer means for compar;ng s;gnals generated by the measuring transducer means w;th the correspond-ing s1gnals ;n the memory means;
computer means for calculating the error between the stored data and signals generated by the measur;ng transducer means to stack the component to achieve an acceptable degree of co1ncidence between the d;men-sions of the reference proflle and the actual component.
Preferably, the apparatus further comprises means for producing a record of the stacking and result~ such as, for example, a pr;nter~ plotter or vlsual d1splay un;t ~VDU) linked to the computer means.
In one embod;ment of the present ;nvent;on, the probe means may be contact;ng probes. The com-ponent may, for example, be mounted on a f;xture, : . .. ... ......
. . : :; .. . .
, :
~ ~ .
`: . ... . . . ' :
~i97~
the fixture being movable in one direction tX-axis) and the component, for example, a turbine blade, may be mounted w;th its principal axis generally perpendicular to the X-axis. The probes may be movable 5 in two mutually perpendicular directions~ the Y and Z-axes, and where the Y-axis is substantially parallel to the blade principal axis. The probe driving motor in the Z-axis may be of the low-torque overdriving .ype.
~y means of a computer program, the probes may be dr;ven in a predetermined sequence to track chordal sections of the aerofo;l. The transducer means on the var;ous direct;on axes measure the d;mens;ons of the aerofoil and compare the measurements obtained with those stored in the memory means and which relate to the dimens;ons which ;t ;s desired to ach;eve.
The data thus acquired is processed - f;rstly to establish dev;atlon between the actual and desired prof;le~ and secondly stacked to establ;sh and accept-able or a best-f;t cond;t;on between actual and des;red~
The latter processing y;elds the sh;fts requ;red to ach;eve best-f;t as well as the resultant prof;le error.
The ;nformat;on relat;ng to the errors between the des;red and actual pro~;les are analysed math-emat1cally by the computer means to establ;sh stack;ng values wh;ch will yield a min;mum value for the sum . :-:
..
. ~ . :,... .
' ;.,,, . ,. :~' 9~t~
of root mean square values of the var;at;ons ;n metal-on condit;on~ Where the shifts ;n the X and Z-axes dictated by the resulting analys;s are insuffic;ent to bring all points of the actual aerofoil profile within the tolerance envelope of the desired aerofoil profile the actual aerofo;l may then be stacked ;ter-at;vely. This process is automatically carried out by the computer means in order to attempt to bring the actual aerofoil within tolerance without hav;ng 1û to scrap or rectify the component. Such iterat;ve stacks, however, may only yield a marginal improvement on the analyt;cal stack.
In one embodiment of apparatus of the present invention the clamp means for holding the component is magnetically coded such that on being attached to the apparatus the appropriate software in the computer memory means is automat;cally down-loaded for gauging the intended component.
In a preferred embodiment of the machine where turbine components such as, for example, blades, may be clamped by unmach~ned features such as roots, the probes may first search for and establish the position in space of cr;tical reference features of the component such as leading and tra;ling edges, for example. The abil1ty of the apparatus to do this means that it no longer becomes dependent on : ,, ,: - , .,~ . . .
,,~
,~
4~
highly accurate machined features on the component in order to place it in a fixed reference position in space. The machine is programmed to search for the component within a relatively wide but well-defined reference envelope and once having located a surface of the component, the driven probes measure the act~al position o~ the component surfaces by continuous, local scanning. This data is then used to redatum the apparatus axes in such a way as to put the critical reference features in the expected position. Where one or more of the component surfaces ;s found to lie, outside the deflned reference envelope, the com puter means arrests the gauging cycle and ;lluminates appropr;ate s;gnals on the apparatus. The operator then checks to see ;f~ for exampLe, the correct clamp-ing means or the correct component has been installed, or that the component has been correctly loaded.
When gaug;ng a component such as a blade, for example, the apparatus computer means may by computer 2û program means gauge two reference aerofoil chordal sections~ usually those near the root and t;p of the camponent. The necessary stack~ng may then be computed and as a result the computer means may then redefine the apparatus axes to compensate for the stack;ng appl;ed. This allows the aerofo;l part of the component to be gauged independently in its ent;rety wlthout reference to unmach;ned component . .. . ..
. : -:
::
~ 7~
root and tip blocks. Thus the accuracy or other~;se of the aerofoil may be verified independently and the data acquired for the redefined apparatus axes may subsequentiy be used to aid in the mach;ning of the root and tip blocks to ensure that the aerofoil is correctly orientated when assembled in a turbine disc, for example.
The motor drive to the probes in the Z-axis may be by a low-torque overdriv;ng motor and to avoid unnecessary stress on the component and probe tips the machine is programmed such that the probes always scan the aerofo;l sect;on ;n a fall;ng mode.
In an alternative embod;ment, non-contact;ng probes may be used, these being especially advantageous for gauging of, for example, delicate ceram;c-type cores used for form;ng the ;nternal passages dur;ng cast;ng of turb;ne components.
All that ;s necessary for the operator to do ;s to load and unload the components from the mach;ne, and even th;s operat;on may be automated by known techn;ques.
The results may be presented ;n graph;cal, tab-ular~ d;agrammatic or electron;c form and coded data may be put d;rectly on to the gauyed components them-Z5 selves by means of, for example, ;nk spray, pen,magnet;c means or s;m;lar mark;ng system. The coded data may be ;n the form of colours, for example, 4~
applied to the component surface, each colour represent-ing a spe~;fic amount of metal to be removed on the area on which the colour lies. aatches of marked components may, therefore, be taken for machining S and subsequently re-gauged and re-marked, ;f necessaryD
Results presented in electronic form are par-ticularly applicable to intercommunication with other numerically-controlled apparatus such as, for example, robot handling equipment.
Accord;ng to a third aspect of the present invent-ion, apparatus for the automatic gauging and mach;ning of engineering components comprises gauging means, handl;ng means and mach;n;ng means, the gauging means having:
means for holding a component to be gauged;
probe means for scanning a surface of the component;
drive means to provide relative motion between the component and the probe means in three mutually perpendicular axes;
measur;ng transducer means associated w~h the drive means and the probe means to generate signals to measure the degree o~ relat;ve movement between the component and the probe;
computer memory means for storing data relat;ng to a re~erence profile hav;ng d;mens;ons wh;ch it is desired to ach;eve;
.; ,.. ;' . .
means for comparing signals generated by the measuring transducer means with the corresponding signals in the memory means;
means for computing the error between the stored S data and the signals generated by the measuring trans-ducer means to stack the component to achieve an acceptable degree of coincidence between the reference profile and the actual component;
handl;ng means for transferring the component from the gaug;ng means to the machining means and back to the gaug;ng means;
computer means for communicating data relating to any residual error from the gauging means to the machining means, and means associated with th~ machining means or w;th the handling means for controlling the degree of mach;n;ng ;n accordance w;th the data commun;cated from the gaug;ng means.
In a preferred embod;ment of the present invent;on the apparatus ~urther compr;ses an automatic componQnt loading and unloading facil;ty for the gaug;ng means such that the apparatus may process batches of compon-ents substantiaLly w;thout ;ntervent10n of an operator.
In one embod;ment o~ the ;nvent;on the handling dev;ce may comprise a known, but su;tably modified robot, which may place the component firstly into clamp;ng means associated with the gauging means , .
- , ':. ' ~' ' ,, ' "' ' . ' '' and then secondly, ;nto clamp;ng and man;puLat;ng means associated with the machining means, and then back in the saUging means for regauging after machining~
Preferably, the mach;ning means may be abrasive belt machining wherein the degree and rate of machining may be t;me and pressure controlled. AlternativeLy, the machining means may, for example, comprise abrasive grit blasting or resilient gr;nd;ng wheels~
Accord;ng to a further aspect of the present invent;on, a method for the automat;c gaug;ng and machin;ng of engineering components includes the steps of:
produc;ng relat;ve movement between the component and probe means ;n three mutually perpendicular axes;
. scanning the component surface w;th the probe means by means of a computer program controlling the relat;ve movement;
generat~ng s;gnals relat;ng to component d;men-s;ons and geometry by transducer means assoc;ated w;th the relatlve movement between the component and the probe means;
compar;ng by computer means the generated s;gnals w;th data stored in computer memory means and wh;ch relates to a reference prof;le wh;ch it is des;red to ach;eve;
calculat;ng the error by computer means between the generated signals and the stored data;
.'~
: .
:~ ', ' .', ' ' stacking the measured component data by computer - means to achieve an acceptable degree of coincidence between the reference profile and the actual component profile;
moving the component by the handl;ng device to machining means;
communicat;ng data relating to any residual dimensionaL error from the gauging means to the machin-ing means, and machin;ng the component ;n accordance with the data relating to the residual dimensional error.
PreferabLy, the component is returned to the gauging means after mach;n;ng in order to conf;rm that an appropriate amount of mater;al has been removed.
Preferably, the process and apparatus may have facil-;t;es whereby components wh;ch meet all d;mensional and shape criter~a are automaticaLly unloaded from the gauging means w;thout be;ng transferred or moved to the mach;ning means. S;m;Larly, thcse components whose dimens;ons are ~ncapable of be;ng rect;f;edr may also be unloaded from the gauging means and scrapped w;thout pass;ng to the mach;nlng means~
In accordance w;th known computer techniques the computer means may be programmed for self-optinl;sation. In;t;ally the computer means controllingthe mach;ning means may be programmed w;th conservative data to ensure that too much mater;al is not removed.
'' . . ' . ,~
; . " ' ~
~8 Thus ;n order to rectify a component several cycles between the gaug;ng means and mach;ning means ~ay be required 3y computing factors relating to, for example, the state of wear of the abrasive belt, the type of material of the component, the degree of metal-on etc~ the number of cycles may eventually be minim;sedn Appropr;ate safeguards must a~ays, however, be employed to prevent excess material removal.
Maximum benefit may be obtained from the invention if the loading and unloading operations for the gauging means are carried out automatically by robotics.
This may be achieved as a subsidiary function of the aforementioned handling device.
Since the mach;n;ng operation ;s an ;ntrinsically longer operation than the gauging operation, it may be feas;bl0 to have one gauging apparatus feed;ng more than one machining station.
In order that the present invent;on may be more fully understood, e~amples w1Ll now be descr;bed by way of illustration only, w;th reference to the accompanying drawlngs of wh;ch:
F;gure 1 shows a schemat;c slde elevation of gauglng aparatus according to the invention;
Figure 2 shows a detail ;n plan v;ew of the probe/component arrangement of Figure 1;
Figure 3 shows the scanning mode of the probes of Figures 1 and 2 on a typical blade aerofoil;
, .
, . . . .. .. . . . .
.. , . ~ . , ,, i. - : -;
.
Figures 4ta), tb) and tc) show reproductions of actual print-outs of the scanning and stacking results of scans around the aerofoil profile at three axial positions for a blade hav;ng passed ;nspection;
Figures Sta), (b) and tc) are similar to Figures 4, but shows a failed blade incapable of being rectified by machining;
Figures 6(a), tb) and tc) are similar to Figure 4, but show an out-of-tolerance blade in the metal-on condition suitable for rect;f;cat;on by mach;ning;
Figure 7 shows a schematic representation of the gauging apparatus of F;gure 1 linked to metal removal means by a handling device for the automatic mach;ning of components.
Referring now to Figures 1 and 2 and where the same features are denoted by common reference numerals.
The gauging apparatus is shown generally at 10. The apparatus compr;ses a rigid frame having a hor;zontal frame member 11 and a vert;cal frame member 12. Mounted on the members 11 and 12 are mach;ne sl;des 13 and 14, respectively, the slides 13 and 14 are dr;ven relat;ve to the members 11 and 12 by pos;t;on;ng mvtors 15 and 16 v;a couplings and lead-screws ~not shown) ;n the X-ax;s and Y-a~;s, respect;vely~ Movement of the sl;des 13 and 14 ;s ..
.. . :~',' ,::, . :
. .
.. , ~ , . : ., ,:
... . . .. .
:,,
~MPROVEMENTS IN OR RELATING TO THE MEASURE~ENT
OF EnGINEERING COMPONENTS
The pr~sent invention relates to the gauging and machining of engineering components having complex curved shapes and particularly to the gauging and machining of components having aerofoil sections such as, for example, blades and nozzle guide vanes for gas and steam turbine engines and compressors.
When a component hav;ng an aerofoil section ;s produced by mach;ning, forging or casting tech-ni~ues, it ;s usually necessary to perform a measuring operation on the component to ensure that it lies within the allowable tolerances pertain;ng to that IS part;cular component. The aerofo;l ;tself often has to sat;sfy tolerances not only on d;mens;ons or thickness relating to a nominal aerofoil profile wh;ch it is des;red to ach;eve at any g;ven sect;on, but also on the actual shape of the sect;on where local areas may have to be constrained within a narrow-er shape tolerance band. Effectively the surface pro~;le oi a chordal sect;on of the aerofo;l must l;e as a whole w1th;n a th;ckness tolerance band whilst each sur~ace of the profile must lie within a narrower shape tolerance band. The shape tolerance band~ however, may be at any position within the th;ckness tolerance band.
~9I~
~, , .... ...~
..
...... ..
~697~
Presently, methods of carrying out these aerofoil measurements largely depend upon how many of the particular component have to be checked. Where the - component in question is a long-run item of which S many repeat batches are likely to be made with total numbers running into thousands~ the preferred method ;s a device known as a multi-point probe. Such devices have, as the;r name suggests, multiple probes wh;ch contact the aerofoil at many points around several sect;ons s;multaneously and compare those sections w;th standard master aerofo;ls on wh;ch the dev;ce has been cal;brated. The ;nformat;on generated ;s usually d;splayed or recorded ;n d;g;tal form on modern vers;ons of the machine and from the information appropriate reci~ication by machining, etc., of the component May be carr;ed out if necessary. Mult;-po;nt probes are very expens;ve and each probe ;s l;m;ted to gauging a s;ngle des;gn of component.
Mult;-point probes are best su;ted to components hav;ng a mult;pl;c;ty of planar ~1.e. non-curved) features and they are used on curved surfaces usually only in those instances where other checks ln the manufacturing process, for example, have g;ven conf;-dence ;n the capab;lity to hold localised shape varia-t;ons ;n controlc Multi-po~nt probes only check the d;menslon at the actual point contacted by the probe itself; ;t cannot guarantee that the slope ., ' .... .. .. .
, ,,"'' ~ "' .
, ~ ~
. .
or d;mension between the contact points is within tolerance~ hence the need for confidence in the manu-~acturing process. The production of multi-point gauges having a sufficiently high resolution to check on shape would require extremely expensive tool;ng.
It is not certain, however, that such gauges would be able to achieve a sufficiently close spacing of the probe array~
At the other end of the scale where only a rela-~;veLy small number of components are envisaged, the methods of aerofoil gauging tend to be more rud;-mentary. Even rud;mentary methods, however, are frequently used in volume product;on. Mechanical comparator gauges are often used where a blank corres-ponding to the des;red aerofo;l shape is clamped;n the device on one side and the component to be checked on the other side. A jockey wheel ~ollows the blank at a chosen sect;on and the probe of a dial gauge follows a corresponding section of the 20 component. The gauge operator observes the dev;at;on of the component from the des;red section and marks up the aerofo;l w;th, for example, an appropriate colour code for subsequent mach;n;ng. Most mach;n;ng ;s carr;ed out by abrasive belt gr;nd;ng. Once the 2S operator has taken action to remove excess metal at a part;cular section, the component has to be ~&j9~7'~1 replaced in the gauge to check whether the action has been adequate~ Even w;th an expensive multi-po;nt probe it is still necessary for the blade to be manually rectified and subsequently re-checked.
S Thus, existing processes for the gauging and nachining of aerofoil components are extremely labour-;ntensive and susceptible to mistakes on the part of the operator.
In between the two extremes of mechanical gauging there are devices known as optical measuring machines or projectors typified by the OMT type of machine.
In th;s method, the component ;s clamped in a fi~ture and the desired aerofo;l sect;on is followed by a roller or stylus wh;ch ;s l;nked to a grat;cule having concentric c;rcles represent;ng var;ous tolerance bands~ A magn;fied ;mage (often X10) of the grat;cule ;s d;splayed on a screen in front of the operator.
A transparent film on wh;ch ;s drawn an acurate prof;le of the des;red aerofo;l, scaled up by a factor equal to the magn;ficat;on be;ng used, ;s placed on the operator's screen so that the image of the concentric c;rcles ;s super;mposed upon the prof;le. The operator follows the actual aerofo;l sect;on on the component with the roller or stylus and s;multaneously views the screen to observe how the grat;cule image wh;ch is follow~ng the component also follows the prof;le of the des;red aerofo;l on the screen. Depend;ng :. .
' :i' . ,: . , , . .
. ~. . .
~ 7~
on wh;ch of the tolerance bands in the grat;cule image coincides with the desired aerofoil profile image will determine whether the blade is in or ou~
o~ ~olerance. The aerofoil may have either excess metal at a particular posit;on or be unders;ze corres-ponding to a metal-on or a metal-off condition~ respect-ivelyu Clearly, ;f a component aerofoil is gauged in a fixed orientation and posit;on w;th reference to a desired aerofo;l also in a fixed orientation and pos;t;on and a metal-off cond;tion perta;ns and the aerofoil is outs;de tolerance ;n that cond;tion, then there is little that can be done in most instances to replace m;ssing metal and the component may, there-fore, be scrap. The actual aerofoil profile itselfmay be within tolerance with regard to both thickness and shape its position in space, however, ~ith respect to same datum such as, for example~ the blade root may be outs;de tolerance. Such pos;t;onal errors of the whole aerofo;l may be compensated for by what are known as stack;ng tolerances~ The whole actual and reference aerofo;ls may be moved relat~ve to each other to ach;eve a best-f;t condlt;on between the two prof;les. The sh;ft requ;red to ach;eve that best-f;t ;s the stacking. Whether or not the component is then with;n tolerance w;ll depend upon the àctual d;mens;onal stack;ng sh;ft made relat;ve 74~
to the stack;ng tolerance allowable on the spec;fic component. Such stack;ng sh;fts may compr;se ;n ~he plane of the aerofoil two linear shifts ;n mutually perpend;cular d;rections plus rotation. Stacklng is, therefore, appl;ed ;n an attempt to br;ng the actual component surface w;thin both the dimensional or thickness and shape tolerances referred to above~
The operator of an OMT-type mach;ne may, therefore, adjust the pos;t;on of the reference aerofo;l with;n an allowable stack;ng tolerance to ach;eve a "best-f;t"~ Thus, the degree of metal-on and metal-off cond;t;ons may be adjusted such that a m;n;mum of metal from a metal-on pos;t;on, ideally on the low pressure surface, has to be removed to br;ng the whole aerofoil sect;on within the requ;red tolerances.
The method still thus necess;tates a high level of operator skill in that he needs to follow the graticule image at all t;mes and must assess the degree of stacking required by a manual ;terative process prior to any actual machin~ng being undertaken on the com-ponent, usually by another operator~ After machinlng, the component aga;n needs to be checked.
Clearly, where mechan;cal comparator gauges are employed and both component and reference blank are in f;xed orientat;on and pos;t;on there ;s no scope whatever for any stack;ng operat;on to be carr;ed out by the operator.
. ,, .. ~ :- -: , . -.,.. ,, ,, , :
....
: .: ., . ,, ",.
74~
In the case of optical measur;ng mach;nes the term "best-fit" used above is not an absolute des-cr;ption but a relative term only. Where the operator has to manually adjust the relat;ve posit;ons of the component and desired aerofo;ls he can only apply, in effect, s;mpl;fied visual criter;a to the operat;on and thus the applied visual "best-fit" w;ll only be the result of the projector operator's judgement.
Such iudgement may vary from operator to operator and also from day to day in the same operator~ The ex;sting methods of applying stack;ng shifts have necessarily been s;mple as heretofore the fac;l;ties to compute the opt;mum stack;ng ;n a machine have been unava;lable.
It is an object of the present invention to prov;de means ~or the gauging of aerofoils which do not rely on expens;ve, dedicated, multi-po;nt probes. It is a further object to provide means for such yaug1ng which are less labour-intensive and require less operator sk;ll than opt;cal measuring machines and mechan;cal comparator gauges.
It ;s a yet further object of the present in-vent;on to provide, in add;t10n to the gauging means stated above, means for the automat;c rectification by machining o~ components~
, , ' .
. ~
.:. . :
:, ; ,.............. ...
-...................... ~ '.; ~ , :. ~ .
7'~
According to a first aspect of the present invent-;on, a method for the automatic gauging of engineering components includes the steps of:
producing relative movement by dr;ve means between the component and probe means in two axes;
scanning the component surface with the probe means by means of a computer prOgraM controlling the relat;ve movement;
generat;ng s.;gnals relating to component dimen-s;ons and geometry by transducer means associated with the relative movement between the component and the probe means;
compar;ng by computer means the generated signals with data stored ;n computer memory means and which relates to a reference prof;le wh;ch it ;s desired to ach;eve;
calculat;ng the error by computer means between the generated,s;gnals and the stored data;
stacking the measured component data by computer means to ach;eve an acceptable degree of co;nc;dence between the reference prof~le and the actual component profile.
According to a second aspect of the present lnvention, apparatus for gauging of turbine components ~5 comprises:
. .
:.. . ::: , :
.. , ~.".
74~
clamp means for holding a component to be gauged;
probe means for scanning a surface of the component;
dr;ve means to provide relative motion between the component and the probe means in three axes;
measuring transducer means associated with the drive means and the probe means to generate signals to measure the degree of movement between the component and the probe means;
computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve;
computer means for compar;ng s;gnals generated by the measuring transducer means w;th the correspond-ing s1gnals ;n the memory means;
computer means for calculating the error between the stored data and signals generated by the measur;ng transducer means to stack the component to achieve an acceptable degree of co1ncidence between the d;men-sions of the reference proflle and the actual component.
Preferably, the apparatus further comprises means for producing a record of the stacking and result~ such as, for example, a pr;nter~ plotter or vlsual d1splay un;t ~VDU) linked to the computer means.
In one embod;ment of the present ;nvent;on, the probe means may be contact;ng probes. The com-ponent may, for example, be mounted on a f;xture, : . .. ... ......
. . : :; .. . .
, :
~ ~ .
`: . ... . . . ' :
~i97~
the fixture being movable in one direction tX-axis) and the component, for example, a turbine blade, may be mounted w;th its principal axis generally perpendicular to the X-axis. The probes may be movable 5 in two mutually perpendicular directions~ the Y and Z-axes, and where the Y-axis is substantially parallel to the blade principal axis. The probe driving motor in the Z-axis may be of the low-torque overdriving .ype.
~y means of a computer program, the probes may be dr;ven in a predetermined sequence to track chordal sections of the aerofo;l. The transducer means on the var;ous direct;on axes measure the d;mens;ons of the aerofoil and compare the measurements obtained with those stored in the memory means and which relate to the dimens;ons which ;t ;s desired to ach;eve.
The data thus acquired is processed - f;rstly to establish dev;atlon between the actual and desired prof;le~ and secondly stacked to establ;sh and accept-able or a best-f;t cond;t;on between actual and des;red~
The latter processing y;elds the sh;fts requ;red to ach;eve best-f;t as well as the resultant prof;le error.
The ;nformat;on relat;ng to the errors between the des;red and actual pro~;les are analysed math-emat1cally by the computer means to establ;sh stack;ng values wh;ch will yield a min;mum value for the sum . :-:
..
. ~ . :,... .
' ;.,,, . ,. :~' 9~t~
of root mean square values of the var;at;ons ;n metal-on condit;on~ Where the shifts ;n the X and Z-axes dictated by the resulting analys;s are insuffic;ent to bring all points of the actual aerofoil profile within the tolerance envelope of the desired aerofoil profile the actual aerofo;l may then be stacked ;ter-at;vely. This process is automatically carried out by the computer means in order to attempt to bring the actual aerofoil within tolerance without hav;ng 1û to scrap or rectify the component. Such iterat;ve stacks, however, may only yield a marginal improvement on the analyt;cal stack.
In one embodiment of apparatus of the present invention the clamp means for holding the component is magnetically coded such that on being attached to the apparatus the appropriate software in the computer memory means is automat;cally down-loaded for gauging the intended component.
In a preferred embodiment of the machine where turbine components such as, for example, blades, may be clamped by unmach~ned features such as roots, the probes may first search for and establish the position in space of cr;tical reference features of the component such as leading and tra;ling edges, for example. The abil1ty of the apparatus to do this means that it no longer becomes dependent on : ,, ,: - , .,~ . . .
,,~
,~
4~
highly accurate machined features on the component in order to place it in a fixed reference position in space. The machine is programmed to search for the component within a relatively wide but well-defined reference envelope and once having located a surface of the component, the driven probes measure the act~al position o~ the component surfaces by continuous, local scanning. This data is then used to redatum the apparatus axes in such a way as to put the critical reference features in the expected position. Where one or more of the component surfaces ;s found to lie, outside the deflned reference envelope, the com puter means arrests the gauging cycle and ;lluminates appropr;ate s;gnals on the apparatus. The operator then checks to see ;f~ for exampLe, the correct clamp-ing means or the correct component has been installed, or that the component has been correctly loaded.
When gaug;ng a component such as a blade, for example, the apparatus computer means may by computer 2û program means gauge two reference aerofoil chordal sections~ usually those near the root and t;p of the camponent. The necessary stack~ng may then be computed and as a result the computer means may then redefine the apparatus axes to compensate for the stack;ng appl;ed. This allows the aerofo;l part of the component to be gauged independently in its ent;rety wlthout reference to unmach;ned component . .. . ..
. : -:
::
~ 7~
root and tip blocks. Thus the accuracy or other~;se of the aerofoil may be verified independently and the data acquired for the redefined apparatus axes may subsequentiy be used to aid in the mach;ning of the root and tip blocks to ensure that the aerofoil is correctly orientated when assembled in a turbine disc, for example.
The motor drive to the probes in the Z-axis may be by a low-torque overdriv;ng motor and to avoid unnecessary stress on the component and probe tips the machine is programmed such that the probes always scan the aerofo;l sect;on ;n a fall;ng mode.
In an alternative embod;ment, non-contact;ng probes may be used, these being especially advantageous for gauging of, for example, delicate ceram;c-type cores used for form;ng the ;nternal passages dur;ng cast;ng of turb;ne components.
All that ;s necessary for the operator to do ;s to load and unload the components from the mach;ne, and even th;s operat;on may be automated by known techn;ques.
The results may be presented ;n graph;cal, tab-ular~ d;agrammatic or electron;c form and coded data may be put d;rectly on to the gauyed components them-Z5 selves by means of, for example, ;nk spray, pen,magnet;c means or s;m;lar mark;ng system. The coded data may be ;n the form of colours, for example, 4~
applied to the component surface, each colour represent-ing a spe~;fic amount of metal to be removed on the area on which the colour lies. aatches of marked components may, therefore, be taken for machining S and subsequently re-gauged and re-marked, ;f necessaryD
Results presented in electronic form are par-ticularly applicable to intercommunication with other numerically-controlled apparatus such as, for example, robot handling equipment.
Accord;ng to a third aspect of the present invent-ion, apparatus for the automatic gauging and mach;ning of engineering components comprises gauging means, handl;ng means and mach;n;ng means, the gauging means having:
means for holding a component to be gauged;
probe means for scanning a surface of the component;
drive means to provide relative motion between the component and the probe means in three mutually perpendicular axes;
measur;ng transducer means associated w~h the drive means and the probe means to generate signals to measure the degree o~ relat;ve movement between the component and the probe;
computer memory means for storing data relat;ng to a re~erence profile hav;ng d;mens;ons wh;ch it is desired to ach;eve;
.; ,.. ;' . .
means for comparing signals generated by the measuring transducer means with the corresponding signals in the memory means;
means for computing the error between the stored S data and the signals generated by the measuring trans-ducer means to stack the component to achieve an acceptable degree of coincidence between the reference profile and the actual component;
handl;ng means for transferring the component from the gaug;ng means to the machining means and back to the gaug;ng means;
computer means for communicating data relating to any residual error from the gauging means to the machining means, and means associated with th~ machining means or w;th the handling means for controlling the degree of mach;n;ng ;n accordance w;th the data commun;cated from the gaug;ng means.
In a preferred embod;ment of the present invent;on the apparatus ~urther compr;ses an automatic componQnt loading and unloading facil;ty for the gaug;ng means such that the apparatus may process batches of compon-ents substantiaLly w;thout ;ntervent10n of an operator.
In one embod;ment o~ the ;nvent;on the handling dev;ce may comprise a known, but su;tably modified robot, which may place the component firstly into clamp;ng means associated with the gauging means , .
- , ':. ' ~' ' ,, ' "' ' . ' '' and then secondly, ;nto clamp;ng and man;puLat;ng means associated with the machining means, and then back in the saUging means for regauging after machining~
Preferably, the mach;ning means may be abrasive belt machining wherein the degree and rate of machining may be t;me and pressure controlled. AlternativeLy, the machining means may, for example, comprise abrasive grit blasting or resilient gr;nd;ng wheels~
Accord;ng to a further aspect of the present invent;on, a method for the automat;c gaug;ng and machin;ng of engineering components includes the steps of:
produc;ng relat;ve movement between the component and probe means ;n three mutually perpendicular axes;
. scanning the component surface w;th the probe means by means of a computer program controlling the relat;ve movement;
generat~ng s;gnals relat;ng to component d;men-s;ons and geometry by transducer means assoc;ated w;th the relatlve movement between the component and the probe means;
compar;ng by computer means the generated s;gnals w;th data stored in computer memory means and wh;ch relates to a reference prof;le wh;ch it is des;red to ach;eve;
calculat;ng the error by computer means between the generated signals and the stored data;
.'~
: .
:~ ', ' .', ' ' stacking the measured component data by computer - means to achieve an acceptable degree of coincidence between the reference profile and the actual component profile;
moving the component by the handl;ng device to machining means;
communicat;ng data relating to any residual dimensionaL error from the gauging means to the machin-ing means, and machin;ng the component ;n accordance with the data relating to the residual dimensional error.
PreferabLy, the component is returned to the gauging means after mach;n;ng in order to conf;rm that an appropriate amount of mater;al has been removed.
Preferably, the process and apparatus may have facil-;t;es whereby components wh;ch meet all d;mensional and shape criter~a are automaticaLly unloaded from the gauging means w;thout be;ng transferred or moved to the mach;ning means. S;m;Larly, thcse components whose dimens;ons are ~ncapable of be;ng rect;f;edr may also be unloaded from the gauging means and scrapped w;thout pass;ng to the mach;nlng means~
In accordance w;th known computer techniques the computer means may be programmed for self-optinl;sation. In;t;ally the computer means controllingthe mach;ning means may be programmed w;th conservative data to ensure that too much mater;al is not removed.
'' . . ' . ,~
; . " ' ~
~8 Thus ;n order to rectify a component several cycles between the gaug;ng means and mach;ning means ~ay be required 3y computing factors relating to, for example, the state of wear of the abrasive belt, the type of material of the component, the degree of metal-on etc~ the number of cycles may eventually be minim;sedn Appropr;ate safeguards must a~ays, however, be employed to prevent excess material removal.
Maximum benefit may be obtained from the invention if the loading and unloading operations for the gauging means are carried out automatically by robotics.
This may be achieved as a subsidiary function of the aforementioned handling device.
Since the mach;n;ng operation ;s an ;ntrinsically longer operation than the gauging operation, it may be feas;bl0 to have one gauging apparatus feed;ng more than one machining station.
In order that the present invent;on may be more fully understood, e~amples w1Ll now be descr;bed by way of illustration only, w;th reference to the accompanying drawlngs of wh;ch:
F;gure 1 shows a schemat;c slde elevation of gauglng aparatus according to the invention;
Figure 2 shows a detail ;n plan v;ew of the probe/component arrangement of Figure 1;
Figure 3 shows the scanning mode of the probes of Figures 1 and 2 on a typical blade aerofoil;
, .
, . . . .. .. . . . .
.. , . ~ . , ,, i. - : -;
.
Figures 4ta), tb) and tc) show reproductions of actual print-outs of the scanning and stacking results of scans around the aerofoil profile at three axial positions for a blade hav;ng passed ;nspection;
Figures Sta), (b) and tc) are similar to Figures 4, but shows a failed blade incapable of being rectified by machining;
Figures 6(a), tb) and tc) are similar to Figure 4, but show an out-of-tolerance blade in the metal-on condition suitable for rect;f;cat;on by mach;ning;
Figure 7 shows a schematic representation of the gauging apparatus of F;gure 1 linked to metal removal means by a handling device for the automatic mach;ning of components.
Referring now to Figures 1 and 2 and where the same features are denoted by common reference numerals.
The gauging apparatus is shown generally at 10. The apparatus compr;ses a rigid frame having a hor;zontal frame member 11 and a vert;cal frame member 12. Mounted on the members 11 and 12 are mach;ne sl;des 13 and 14, respectively, the slides 13 and 14 are dr;ven relat;ve to the members 11 and 12 by pos;t;on;ng mvtors 15 and 16 v;a couplings and lead-screws ~not shown) ;n the X-ax;s and Y-a~;s, respect;vely~ Movement of the sl;des 13 and 14 ;s ..
.. . :~',' ,::, . :
. .
.. , ~ , . : ., ,:
... . . .. .
:,,
2 ~ 7 measured by transducers 17 and 18~ respectively.
On the slide 14 is mounted a cross-slide 19 which moves in the Z-axis. The slide 19 is driven by a low-torque overdriving motor 20 via a rack and pinion S gear assembly 21. Dr;ven from ~he slide 19, also by a rack and pinion gear assembly 22, is an encoder 23. The encoder 23 generates positional signals relating to probes 24 and 25 which are mownted on a carrying frame 26 which is itself mounted on the slide 19. Mounted on the slide 13 is a mounting clamp 27 for holding the component 28, in this instance a gas turbine engine blade, which is to be gauged.
A computer 29, programmed for both control 29a and data processing 29b functions is linked to the appara tus 10 via motor drive electronics 29c and data acquisi-tion electronics 29d. The dr;ve electron;cs 29c ;s connected to the motors 15, 16 and 17. The data acqu;s;t;on electron;cs p9cks up signals from trans-ducers 17 and 18, the encoder 23 and other sensors not shown. The dr;ve electron;cs 29c and data acqu;s;-tion electronics 29d ;nclude analogue/dig;tal convert-ers as necessary to make the data amenable to computer processing. The s;gnals transm;tted v;a the dr;ve electron1cs are generated in accordance with so~tware relevant to the component be;ng gauged stored in compwter memory 29f and s;gnals fed back from the transducers 17 and 18 and encoder 23. L;nked to outputs from computer 2q is a V~U 30a indicating d;rectly the results of gauging~ a plotter 30b for g;ving hard copy results in graphical form and a printer 30c for giving more detailed results in tabular 5 ~orm. The print-out ~rom plotter 30b is in the form of geometric representations of the aerofo;l profile 310 together with dimensional and stacking data relatin to those profiles (see Figures 4, S and 6). The apparatus is also, of course, fittPd with various control switches, actuators and sensors tnot shown) for in;tiating and stopp;ng the apparatus.
In operation, and now also referring to F;gure
On the slide 14 is mounted a cross-slide 19 which moves in the Z-axis. The slide 19 is driven by a low-torque overdriving motor 20 via a rack and pinion S gear assembly 21. Dr;ven from ~he slide 19, also by a rack and pinion gear assembly 22, is an encoder 23. The encoder 23 generates positional signals relating to probes 24 and 25 which are mownted on a carrying frame 26 which is itself mounted on the slide 19. Mounted on the slide 13 is a mounting clamp 27 for holding the component 28, in this instance a gas turbine engine blade, which is to be gauged.
A computer 29, programmed for both control 29a and data processing 29b functions is linked to the appara tus 10 via motor drive electronics 29c and data acquisi-tion electronics 29d. The dr;ve electron;cs 29c ;s connected to the motors 15, 16 and 17. The data acqu;s;t;on electron;cs p9cks up signals from trans-ducers 17 and 18, the encoder 23 and other sensors not shown. The dr;ve electron;cs 29c and data acqu;s;-tion electronics 29d ;nclude analogue/dig;tal convert-ers as necessary to make the data amenable to computer processing. The s;gnals transm;tted v;a the dr;ve electron1cs are generated in accordance with so~tware relevant to the component be;ng gauged stored in compwter memory 29f and s;gnals fed back from the transducers 17 and 18 and encoder 23. L;nked to outputs from computer 2q is a V~U 30a indicating d;rectly the results of gauging~ a plotter 30b for g;ving hard copy results in graphical form and a printer 30c for giving more detailed results in tabular 5 ~orm. The print-out ~rom plotter 30b is in the form of geometric representations of the aerofo;l profile 310 together with dimensional and stacking data relatin to those profiles (see Figures 4, S and 6). The apparatus is also, of course, fittPd with various control switches, actuators and sensors tnot shown) for in;tiating and stopp;ng the apparatus.
In operation, and now also referring to F;gure
3, the blade 28 is loaded into the mounting clamp 27 with the major axis of the blade generally parallel to the Y-axis. The gaug;ng sequence is initiated by pressing the appropriate switch. The program stored in the computer memory 29f starts the motor 16 via the control function 29a and motor dr;ve elec-tronics 29c and drives the slide 14 unt;l the probes Z0 24 and 25 are ;n the correct Y-co-ord;nate pos;t;on, as related to the camputer by transducer 18, to begin scanning the des;red sect;on of the blade 2B. The rnotor 15 then dr;ves the blade 28 towards and between the probes 24 and 25 where the component ;s arrested at pqsition 'A', the "highest" point on the blade profile convex surface. The motor 20 via the slide :,. ~ .
19 moves the probe 25 towards the blade 28 (since the probes 24 and 25 are a f;xed relationship to e~ch other, probe 24 moves away from the blade).
On contacting the blade, the probe 25 stops due to the motor 20 being stalled, and the motor 15 then drives the blade in the X1 direction, the probe 25 rema;ns in contact w;th and in a falling mode with respect to the blade, dr;ven by the motor 20, unt;l it reaches posit;on 'D' where the probe 25 accelerates rap;dly ;n the Z1 d;rection. The probe 25 and sl;de 13 are halted by the computer wh;ch recogn;ses, due to the program, that the probe 25 has exceeded the d;mens;ons of an envelope ;n wh;ch the aerofo;l must l;e. Probe 25 ;s then retracted to allow the blade profile 31 to move in the X2 direction to position 'C' relative to the probe axis. Probe 24 is then moved towards the blade 28 in the position 'C'.
On reach;ng the blade, the probe 24 stops and the blade ;s then moved ;n the X2 d;rection and all the time the probe 24 ;s dr;ven aga;nst the blade, aga;n ~n a ~all;ng mode, unt;l pos;t;on 'A' ;s reached, the "lowest" po;nt of the blade under-cambered surface.
On reach1ng 'A' the X-traverse is halted and probe 25 ;s moved towards the blade. On contact;ng the blade, the X-traverse, aga;n in the X2 direct;on ;s continued until the probe 25 reaches the trailing edge just to the left of pos;t;on '~' where aga;n ': ,, ,. ~ . . .
the probe 25 rapidly accelerates ;n the Z1 direct;on and ;s hatted and retracted under command of the computer program. The same process of cont;nuousty scann;ng the blade profile 31 ;n a number of sub-S scans, always w;th the probes 24 or 25 ;n a fall;ngmode, continues unt;l the complete profile 31 has been gauged. This appl;es also to the relat;vely short reg;ons scanned by probe 24 to the left of posit;on 'B' in the X2 direct;on and to the right of position 'C' in the X1 d;rect;on. All the wh;le, the relat;ve movements between the blade 28 and the probes 24 and 25 are controlled by the program in the computer 29. Simultaneously, the transducers 17 and 18 and encoder 23 are supplying positional s;gnals relat;ng to the blade profile 31 dimensions to the computer 29 where these results are compared with the required pro~;le and tolerances stored in the computer's memory. The computer then analyses the results obta;ned and calculates ,the requ;red shifts ln the X and Z axes and any rotational stacking necessary to maximise the degree o~ coincidence between the actual prof1le 31 and the requ;red prof;le stored ;n the comp,uter 29 memory. Where the ach;evement o~ maximum co;nc;dence between actual and des;red profiles results in exceeding the stack;ng tolerance the computer re-analyses the data to ach;eve an accept-able degree of co;ncidence wh;ch ;s within tolerance : ~ . "~..
.::. . .
:
.. . .. .
of the actual and desired profiles and which is also with;n the allowable stacking tolerance if this i-s possible. The calculations thus made are then produced as geometric representations of the profile 31 by the printer 30. The motor 16 then pos;tions the probes 24 and 25 at the appropriate Y-co-ordinate for the next blade section to be scanned, and the above process is repeated. Three sections on the blade 28 are scanned and prof;les 31 are produced by the plotter 30b in the form shown in Figures 4~a~, ~b) and ~c), 5~a), ~b~ and tc), and 6~a), ~b) and ~c~, the Figures 4, 5 and 6 hav;ng been copied from actual print-outs from plotter 30b.
It should be noted that although the blade profile 31 shown in Figure 3 shows the "highest" po;nt on the convex surface and "lowest" po;nt on the under-cambered surface co;nc;dent at pos;t;on 'A' for s;m-plicity of descr;pt;on th;s s;tuat;on rarely perta;ns ;n pract;ce~ The computer program is such that the pOS;t;OI1S of the "h;ghest" and "lowest" points of the prof;le are computed from acqu;red date for ;n every case thus the descr;ptlon relating to F;gure 3 ;s a part;cular case where these two po;nts do coinc;de.
Referr;ng now to F1gures 4, 5 and 6. F;gure
19 moves the probe 25 towards the blade 28 (since the probes 24 and 25 are a f;xed relationship to e~ch other, probe 24 moves away from the blade).
On contacting the blade, the probe 25 stops due to the motor 20 being stalled, and the motor 15 then drives the blade in the X1 direction, the probe 25 rema;ns in contact w;th and in a falling mode with respect to the blade, dr;ven by the motor 20, unt;l it reaches posit;on 'D' where the probe 25 accelerates rap;dly ;n the Z1 d;rection. The probe 25 and sl;de 13 are halted by the computer wh;ch recogn;ses, due to the program, that the probe 25 has exceeded the d;mens;ons of an envelope ;n wh;ch the aerofo;l must l;e. Probe 25 ;s then retracted to allow the blade profile 31 to move in the X2 direction to position 'C' relative to the probe axis. Probe 24 is then moved towards the blade 28 in the position 'C'.
On reach;ng the blade, the probe 24 stops and the blade ;s then moved ;n the X2 d;rection and all the time the probe 24 ;s dr;ven aga;nst the blade, aga;n ~n a ~all;ng mode, unt;l pos;t;on 'A' ;s reached, the "lowest" po;nt of the blade under-cambered surface.
On reach1ng 'A' the X-traverse is halted and probe 25 ;s moved towards the blade. On contact;ng the blade, the X-traverse, aga;n in the X2 direct;on ;s continued until the probe 25 reaches the trailing edge just to the left of pos;t;on '~' where aga;n ': ,, ,. ~ . . .
the probe 25 rapidly accelerates ;n the Z1 direct;on and ;s hatted and retracted under command of the computer program. The same process of cont;nuousty scann;ng the blade profile 31 ;n a number of sub-S scans, always w;th the probes 24 or 25 ;n a fall;ngmode, continues unt;l the complete profile 31 has been gauged. This appl;es also to the relat;vely short reg;ons scanned by probe 24 to the left of posit;on 'B' in the X2 direct;on and to the right of position 'C' in the X1 d;rect;on. All the wh;le, the relat;ve movements between the blade 28 and the probes 24 and 25 are controlled by the program in the computer 29. Simultaneously, the transducers 17 and 18 and encoder 23 are supplying positional s;gnals relat;ng to the blade profile 31 dimensions to the computer 29 where these results are compared with the required pro~;le and tolerances stored in the computer's memory. The computer then analyses the results obta;ned and calculates ,the requ;red shifts ln the X and Z axes and any rotational stacking necessary to maximise the degree o~ coincidence between the actual prof1le 31 and the requ;red prof;le stored ;n the comp,uter 29 memory. Where the ach;evement o~ maximum co;nc;dence between actual and des;red profiles results in exceeding the stack;ng tolerance the computer re-analyses the data to ach;eve an accept-able degree of co;ncidence wh;ch ;s within tolerance : ~ . "~..
.::. . .
:
.. . .. .
of the actual and desired profiles and which is also with;n the allowable stacking tolerance if this i-s possible. The calculations thus made are then produced as geometric representations of the profile 31 by the printer 30. The motor 16 then pos;tions the probes 24 and 25 at the appropriate Y-co-ordinate for the next blade section to be scanned, and the above process is repeated. Three sections on the blade 28 are scanned and prof;les 31 are produced by the plotter 30b in the form shown in Figures 4~a~, ~b) and ~c), 5~a), ~b~ and tc), and 6~a), ~b) and ~c~, the Figures 4, 5 and 6 hav;ng been copied from actual print-outs from plotter 30b.
It should be noted that although the blade profile 31 shown in Figure 3 shows the "highest" po;nt on the convex surface and "lowest" po;nt on the under-cambered surface co;nc;dent at pos;t;on 'A' for s;m-plicity of descr;pt;on th;s s;tuat;on rarely perta;ns ;n pract;ce~ The computer program is such that the pOS;t;OI1S of the "h;ghest" and "lowest" points of the prof;le are computed from acqu;red date for ;n every case thus the descr;ptlon relating to F;gure 3 ;s a part;cular case where these two po;nts do coinc;de.
Referr;ng now to F1gures 4, 5 and 6. F;gure
4 shows that all three sect;ons of the blade scanned have passed and, therefore, that blade has met the .. ' ~ ,.
. ;, , customer's inspection requirements. In F;gure 4(b), for example, the stacking sh;fts requ;red to produce maximum co;nc;dence between the actual profile 31 and the requ;red prof;le 32 was +0.0005" ;n the X
direct;on, ~O.Oû18" in the Z direction and an anti clockwise rotation of 1.844'. The aerofoil by these stacking shifts, wh;ch are themselves within tolerance, has been rendered compLetely with;n tolerance and requires no rect;f;cation. Figures 5(a), ~b) and (c) depict the prof;les obta;ned on a blade of the same type as that of Figure 4 but wh;ch has failed completely as a result of being under-size. tt may be seen in ~a) and ~b) that the sections have failed as a result of being under-size, ~a) at the trailing edge, ~b) and (c) at the leading edge. The stacking has been opt;m;sed to m;n;mise the out-of-tolerance feature, but ;t ;s not poss;ble under any stack;ng c;rcumstances to render the actual prof;le 31 w;th;n tolerance w;th respect to the des;red prof;le 32.
2a The section shown at Figure 5(c) has been rejected both for be;ng out-of-tolerance on dimens;ons at the lead;ng edge and also for being outs;de the stack;ng tolerance~ It can be seen from the data presented ;n the pr;nt-out shown ln F;gure Stc) that ;n order to ach;eve a best-f;t of the actual prof;le 31 w;th that of the desired profile 32, the stacking tolerance .. . .
..: : . ' :
:.
. ': ' .X~9 has been exceeded in that an ant;-clockwise rotat;on of 24.903' was requ;red to ach;eve a best-f;t. In the actual print-out from plotter ~Qb this stacking figure is printed in red.
Figure 6 shows a set of blade aerofoil scans where they have again failed on thickness. However, this failure is because of a metal-on cond;t;on which can be rectified by mach;ning. Although not apparent from Figures 4, S and 6 the colours used to pr;nt thè d;mens;ons vary accord;ng to the metal cond;tion.
Thus, where the dimens;ons are w;th;n tolerance these are pr;nted ;n green, metal-off or other unrectifiable tolerance fa;lures are ;n red with negative s;gn where appropriate and metal-on is ;n blue. In F;gures 6(a), tb) and (c) those figures r;nged are metal-on and may be rect;f;ed by mach;ning. It may be seen that the computer is programmed to stack the data such that most mater;al which needs to be removed is on the more eas;ly accessible convex or low pressure face of the aerofo;l~
Referr;ng now to Figure 7~ Gauging apparatus ;s shown generally at 10 w;th a blade 28 held ;n the apparatus 10. Linked to the apparatus 10 1s a computer 29 wh;ch is spl;t up ;nto the various funct;ons as descr;bed w1th reference to Figure 1 and which supplies control signals to the apparatus ''~'.''` " ' . .
.
~' '' ,- " ~
7~
10 and receives signals relating to the component dimens;ons and geometry from the apparatus ~00 Sited close to the apparatus 10 is a robot shown generally at 40 and which comprises a gripper 41 adapted to hold the blade 28 the gripper being at the end of a jointed manipulating arm 42. Also situated be~ween the end of the manipulating arm 42 and the gripper 41 ;s a pressure sens;ng device 43 w;th transducers to prov;de signals ~or control purposes. Operation o~ the robot 40 ;s effected by computer 44 which provides control signals to the manipulating arm 42 and receives ;nformat;on signals from the pressure sens;ng device 43. Computers 29 and 44 are l;nked to commun;cate w;th each other. S;ted close to the robot 40 ;s an abras;ve belt mach;n;ng dev;ce 50 having dr;ve wheels 51 around wh;ch an abras;ve belt 52 passesO
In operat;on the gauging apparatus 10 funct;ons as described above w;th re-ference to F;gures 1 to 3. The necessary data is computed by the computer and ;s commun;cated from the computer 29 to the computer 44 wh;ch controLs the operatlon of the robot 40 wh;ch removes the blade 28 from the gauglng apparatus and transfers ;t to the belt l;n;sh;ng mach;ne SO
by means of the gripper 41 and manipulat;ng arm 42 tboth shown as dotted l;nes). Metal ;s removed by ' ,; .,, ' ' ' , ,: ,.
presenting ~he appropriate areas of the blade to the abras;ve belt 52~ The rate and amount of metal removed is controlled by the pressure and time of abrasion, the pressure being measured by the sensor 43 and controlled by the computer 44. Where metal has ~o be removed from adiacent areas on an aerofoil, the rates of pressure increase and decrease are ramped to provide smoothly blended contours. When suffic;ent metal in accordance with signals supplied from computer 29 to computer 44 has been removed, the robot 40 transfers the blade 28 back to the gauging apparatus 10 for re-gauging. If, on re-gauging, the blade is st;ll found to be outside tolerance with a metal-on condition, ;t ;s transferred back to the abras;ve belt linisher 50 for further processing as before.
If, however, the blade ;s now found to be with;n tolerance, ;t ;s removed from the machine and a new blade loaded for gaug;ng.
Further ref;nements to the descr;bed apparatus may be made~ For e~ample, automated loading and unload;ng oF the gauging apparatus may be ;ncluded, e;ther by dedicated loader/unloader apparatus wh;ch ~s also controlled by computer and actuated by the gauglng apparatus declar;ng a component to be with;n tolerance or a total reject and thus ;n;tiat;ng the loading/unload;ng apparatus to remove the component ;
.
to an appropriate store and load a new component for gauging. Alternat;vely, the robot 40 may be further programmed to load and unload the gauging apparatus 10, in add;tion to transferring the component S between gaug;ng apparatus 10 and abras;ve belt mach;ne 50. Pressure sensors may be associated with the machining means rather than w;th the handling robot 40.
Xn an alternative embodiment the robot 40 may merely transfer the component between the gauging means and the mach;n;ng means. The mach;ning means may have a ded;cated manipulating dev;ce assoc;ated w;th ;t for man;pulating the component. In such an embodiment computer means would also be l;nked to the machin;ng means man;pulat;ng dev;ce.
It w;ll be apprec;ated that the present invent;on is not lim;ted In scope to the examples g;ven and that ;t ;s equally appl;cable to the gaug;ng and rectiflcation of many eng;neer;ng,components hav;ng complex curved surfaces, especially where such com-ponents are relatively th;n and flexible and not amenable to mach;n;ng by convent;onal metal cutt;ng methods such as mill;ng and turn1ng.
. . . .
:: .
-, . . ... .
. ;, , customer's inspection requirements. In F;gure 4(b), for example, the stacking sh;fts requ;red to produce maximum co;nc;dence between the actual profile 31 and the requ;red prof;le 32 was +0.0005" ;n the X
direct;on, ~O.Oû18" in the Z direction and an anti clockwise rotation of 1.844'. The aerofoil by these stacking shifts, wh;ch are themselves within tolerance, has been rendered compLetely with;n tolerance and requires no rect;f;cation. Figures 5(a), ~b) and (c) depict the prof;les obta;ned on a blade of the same type as that of Figure 4 but wh;ch has failed completely as a result of being under-size. tt may be seen in ~a) and ~b) that the sections have failed as a result of being under-size, ~a) at the trailing edge, ~b) and (c) at the leading edge. The stacking has been opt;m;sed to m;n;mise the out-of-tolerance feature, but ;t ;s not poss;ble under any stack;ng c;rcumstances to render the actual prof;le 31 w;th;n tolerance w;th respect to the des;red prof;le 32.
2a The section shown at Figure 5(c) has been rejected both for be;ng out-of-tolerance on dimens;ons at the lead;ng edge and also for being outs;de the stack;ng tolerance~ It can be seen from the data presented ;n the pr;nt-out shown ln F;gure Stc) that ;n order to ach;eve a best-f;t of the actual prof;le 31 w;th that of the desired profile 32, the stacking tolerance .. . .
..: : . ' :
:.
. ': ' .X~9 has been exceeded in that an ant;-clockwise rotat;on of 24.903' was requ;red to ach;eve a best-f;t. In the actual print-out from plotter ~Qb this stacking figure is printed in red.
Figure 6 shows a set of blade aerofoil scans where they have again failed on thickness. However, this failure is because of a metal-on cond;t;on which can be rectified by mach;ning. Although not apparent from Figures 4, S and 6 the colours used to pr;nt thè d;mens;ons vary accord;ng to the metal cond;tion.
Thus, where the dimens;ons are w;th;n tolerance these are pr;nted ;n green, metal-off or other unrectifiable tolerance fa;lures are ;n red with negative s;gn where appropriate and metal-on is ;n blue. In F;gures 6(a), tb) and (c) those figures r;nged are metal-on and may be rect;f;ed by mach;ning. It may be seen that the computer is programmed to stack the data such that most mater;al which needs to be removed is on the more eas;ly accessible convex or low pressure face of the aerofo;l~
Referr;ng now to Figure 7~ Gauging apparatus ;s shown generally at 10 w;th a blade 28 held ;n the apparatus 10. Linked to the apparatus 10 1s a computer 29 wh;ch is spl;t up ;nto the various funct;ons as descr;bed w1th reference to Figure 1 and which supplies control signals to the apparatus ''~'.''` " ' . .
.
~' '' ,- " ~
7~
10 and receives signals relating to the component dimens;ons and geometry from the apparatus ~00 Sited close to the apparatus 10 is a robot shown generally at 40 and which comprises a gripper 41 adapted to hold the blade 28 the gripper being at the end of a jointed manipulating arm 42. Also situated be~ween the end of the manipulating arm 42 and the gripper 41 ;s a pressure sens;ng device 43 w;th transducers to prov;de signals ~or control purposes. Operation o~ the robot 40 ;s effected by computer 44 which provides control signals to the manipulating arm 42 and receives ;nformat;on signals from the pressure sens;ng device 43. Computers 29 and 44 are l;nked to commun;cate w;th each other. S;ted close to the robot 40 ;s an abras;ve belt mach;n;ng dev;ce 50 having dr;ve wheels 51 around wh;ch an abras;ve belt 52 passesO
In operat;on the gauging apparatus 10 funct;ons as described above w;th re-ference to F;gures 1 to 3. The necessary data is computed by the computer and ;s commun;cated from the computer 29 to the computer 44 wh;ch controLs the operatlon of the robot 40 wh;ch removes the blade 28 from the gauglng apparatus and transfers ;t to the belt l;n;sh;ng mach;ne SO
by means of the gripper 41 and manipulat;ng arm 42 tboth shown as dotted l;nes). Metal ;s removed by ' ,; .,, ' ' ' , ,: ,.
presenting ~he appropriate areas of the blade to the abras;ve belt 52~ The rate and amount of metal removed is controlled by the pressure and time of abrasion, the pressure being measured by the sensor 43 and controlled by the computer 44. Where metal has ~o be removed from adiacent areas on an aerofoil, the rates of pressure increase and decrease are ramped to provide smoothly blended contours. When suffic;ent metal in accordance with signals supplied from computer 29 to computer 44 has been removed, the robot 40 transfers the blade 28 back to the gauging apparatus 10 for re-gauging. If, on re-gauging, the blade is st;ll found to be outside tolerance with a metal-on condition, ;t ;s transferred back to the abras;ve belt linisher 50 for further processing as before.
If, however, the blade ;s now found to be with;n tolerance, ;t ;s removed from the machine and a new blade loaded for gaug;ng.
Further ref;nements to the descr;bed apparatus may be made~ For e~ample, automated loading and unload;ng oF the gauging apparatus may be ;ncluded, e;ther by dedicated loader/unloader apparatus wh;ch ~s also controlled by computer and actuated by the gauglng apparatus declar;ng a component to be with;n tolerance or a total reject and thus ;n;tiat;ng the loading/unload;ng apparatus to remove the component ;
.
to an appropriate store and load a new component for gauging. Alternat;vely, the robot 40 may be further programmed to load and unload the gauging apparatus 10, in add;tion to transferring the component S between gaug;ng apparatus 10 and abras;ve belt mach;ne 50. Pressure sensors may be associated with the machining means rather than w;th the handling robot 40.
Xn an alternative embodiment the robot 40 may merely transfer the component between the gauging means and the mach;n;ng means. The mach;ning means may have a ded;cated manipulating dev;ce assoc;ated w;th ;t for man;pulating the component. In such an embodiment computer means would also be l;nked to the machin;ng means man;pulat;ng dev;ce.
It w;ll be apprec;ated that the present invent;on is not lim;ted In scope to the examples g;ven and that ;t ;s equally appl;cable to the gaug;ng and rectiflcation of many eng;neer;ng,components hav;ng complex curved surfaces, especially where such com-ponents are relatively th;n and flexible and not amenable to mach;n;ng by convent;onal metal cutt;ng methods such as mill;ng and turn1ng.
. . . .
:: .
-, . . ... .
Claims (15)
1. A method for the automatic gauging of engineering components the method comprising the steps of:
producing relative movement by drive means between said component and probe means in two mutually perpen-dicular axes;
scanning said component surface with said probe means by means of a computer program controlling the relative movement;
generating signals relating to component dimen-sions and geometry by transducer means associated with the relative movement between said component and said probe means;
comparing by computer means the generated signals with data stored in computer memory means and which relates to a reference profile which it is desired to achieve;
calculating the error by computer means between said generated signals and said stored data;
stacking the measured component data by computer means to maximise desired coincidence between said reference profile and the actual component profile.
producing relative movement by drive means between said component and probe means in two mutually perpen-dicular axes;
scanning said component surface with said probe means by means of a computer program controlling the relative movement;
generating signals relating to component dimen-sions and geometry by transducer means associated with the relative movement between said component and said probe means;
comparing by computer means the generated signals with data stored in computer memory means and which relates to a reference profile which it is desired to achieve;
calculating the error by computer means between said generated signals and said stored data;
stacking the measured component data by computer means to maximise desired coincidence between said reference profile and the actual component profile.
2. A method for the automatic gauging of engineering components according to Claim 1 and wherein said engineering component does not require to have any machined datum features and the computer means is programmed to search for and locate component reference features within an envelope defined in said computer memory means.
3. A method for the automatic gauging of engineering components according to Claim 2 and wherein said engineering component includes an aerofoil the method being further characterised in that said aerofoil is first gauged on at least two chordal sections, the data being then computed by computer means to provide shifts and further to redefine apparatus reference axes to yield data for subsequent machining of other component features such as root and tip blocks.
4. A method for the automatic gauging of engineering components according to Claim 1 and wherein the gauged component is marked with data to assist in subsequent machining for bringing the actual profile into conform-ity with said reference profile.
5. A method according to Claim 4 and wherein said component is marked with magnetically coded data.
6. A method according to Claim 4 and wherein said component is marked with colour coded data.
7. A method according to Claim 1 and wherein the computed data is recorded or displayed in graphical, tabulated or diagrammatic form.
8. Apparatus for the automatic gauging of engineering components the apparatus comprising:
clamp means for holding a component to be gauged;
probe means for scanning a surface of said component;
drive means to provide relative motion between said component and said probe means in three mutually perpendicular axes;
measuring transducer means associated with said drive means and said probe means to generate signals to measure the degree of movement between said component and said probe means;
computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve;
computer means for comparing signals generated by said measuring transducer means with the correspond-ing signals in said computer memory means;
computer means for calculating the error between the stored data and said signals generated by the measuring transducer means to stack the components to maximise desired coincidence between the dimensions of said reference profile and the actual component.
clamp means for holding a component to be gauged;
probe means for scanning a surface of said component;
drive means to provide relative motion between said component and said probe means in three mutually perpendicular axes;
measuring transducer means associated with said drive means and said probe means to generate signals to measure the degree of movement between said component and said probe means;
computer memory means for storing data relating to a reference profile having dimensions which it is desired to achieve;
computer means for comparing signals generated by said measuring transducer means with the correspond-ing signals in said computer memory means;
computer means for calculating the error between the stored data and said signals generated by the measuring transducer means to stack the components to maximise desired coincidence between the dimensions of said reference profile and the actual component.
9. Apparatus according to Claim 8 and wherein said apparatus further comprises means for producing a record or display of the computed data.
10. Apparatus according to Claim 8 and wherein said probes are contacting probes driven by electric motor drive means.
11. Apparatus according to Claim 8 and wherein said probes are non-contacting probes.
12. Apparatus according to Claim 8 and wherein said apparatus further includes means to mark said component being gauged with coded information for subsequent rectification by machining.
13. Apparatus according to Claim 8 and wherein said computer means are programmed such that said probes first search for said component within a defined envelope.
14. Apparatus according to Claim 8 and wherein said engineering component to be gauged includes an aerofoil.
15. Apparatus according to Claim 8 and wherein said clamp means is magnetically coded such that on being installed in said apparatus the correct computer software for the component being gauged is down loaded into said computer memory means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB858508391A GB8508391D0 (en) | 1985-03-30 | 1985-03-30 | Measurement of engineering components |
| GB8508391 | 1985-03-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1269741A true CA1269741A (en) | 1990-05-29 |
Family
ID=10576979
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000504566A Expired - Fee Related CA1269741A (en) | 1985-03-30 | 1986-03-20 | Measurement of engineering components |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4811253A (en) |
| EP (1) | EP0199961B1 (en) |
| JP (1) | JPS61226605A (en) |
| CA (1) | CA1269741A (en) |
| DE (1) | DE3685362D1 (en) |
| GB (1) | GB8508391D0 (en) |
Families Citing this family (48)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8508390D0 (en) * | 1985-03-30 | 1985-05-09 | Ae Plc | Measurement & machining engineering components |
| JPS62248009A (en) * | 1986-04-22 | 1987-10-29 | Mitsubishi Electric Corp | Numerical controller |
| GB2230363B (en) * | 1986-08-04 | 1991-01-09 | Fmc Corp | Computer integrated gaging system |
| GB2202659B (en) * | 1987-02-23 | 1991-07-17 | Mitutoyo Corp | Coordinate measuring instrument and method of generating pattern data concerning shape of work to be measured |
| IT1211390B (en) * | 1987-10-06 | 1989-10-18 | Dea Spa | INTERACTIVE GRAPHIC SYSTEM FOR THE MATHEMATIZATION OF PHYSICAL MODELS |
| EP0312634B1 (en) * | 1987-10-22 | 1994-07-20 | Mitsubishi Denki Kabushiki Kaisha | Numerical control equipment |
| US5051933A (en) * | 1988-05-20 | 1991-09-24 | The Boeing Company | Method and apparatus for measuring the waviness of an aerodynamic surface |
| US4920495A (en) * | 1988-07-15 | 1990-04-24 | Gfm Holdings Ag | Sheet cutting machine |
| US4959523A (en) * | 1988-11-18 | 1990-09-25 | Hydro-Quebec | Method and apparatus for automatically sensing the configuration of a surface area and effecting a work function thereon |
| US5047966A (en) * | 1989-05-22 | 1991-09-10 | Airfoil Textron Inc. | Airfoil measurement method |
| US5055752A (en) * | 1990-04-20 | 1991-10-08 | United Technologies Corporation | Method for machining airfoils |
| US5208763A (en) * | 1990-09-14 | 1993-05-04 | New York University | Method and apparatus for determining position and orientation of mechanical objects |
| NL9002864A (en) * | 1990-12-21 | 1992-07-16 | Turbine Support Europa B V | REPAIR OF SHOVES FROM GASTURBINE ENGINES. |
| EP0496004B1 (en) * | 1991-01-15 | 1996-11-06 | Kapp GmbH & Co. KG Werkzeugmaschinenfabrik | Method for high-precision machining of pre-profiled, hardened workpieces |
| US6041271A (en) * | 1991-10-10 | 2000-03-21 | Finn-Power International, Inc. | Apparatus to determine the operational effectiveness of a machine tool and method therefor |
| CA2135620A1 (en) * | 1992-05-01 | 1993-11-11 | Zev Galel | Autonomous selective cutting, method and apparatus |
| US5285572A (en) * | 1992-08-12 | 1994-02-15 | General Electric Company | Method and system for machining contoured parts |
| US6175415B1 (en) | 1997-02-19 | 2001-01-16 | United Technologies Corporation | Optical profile sensor |
| US6106204A (en) * | 1997-09-05 | 2000-08-22 | United Technologies Corporation | Apparatus for forming the edge of an airfoil |
| US6449529B1 (en) | 1999-01-05 | 2002-09-10 | Henryk Oleksy | Process for contour machining of metal blocks |
| GB2345455B (en) * | 1999-01-06 | 2002-11-06 | M J Technologies Ltd | Method of micromachining aerofoil components |
| US6209216B1 (en) | 1999-08-16 | 2001-04-03 | General Electric Company | Methods and apparatus for measuring airfoil coordinates |
| US6611731B2 (en) | 1999-12-13 | 2003-08-26 | M J Technologies Limited | Micromachining aerofoil components |
| US20020092190A1 (en) * | 2001-01-16 | 2002-07-18 | Hofer Douglas Carl | Trailing edge thickness measurement method and apparatus |
| US6604285B2 (en) * | 2001-06-07 | 2003-08-12 | General Electric Company | Method and apparatus for electronically determining nozzle throat area and harmonics |
| US7372558B2 (en) * | 2001-10-11 | 2008-05-13 | Laser Projection Technologies, Inc. | Method and system for visualizing surface errors |
| US7259552B2 (en) | 2002-05-31 | 2007-08-21 | Siemens Power Generation, Inc. | Wear monitor for turbo-machine |
| GB0400144D0 (en) * | 2004-01-06 | 2004-02-11 | Renishaw Plc | Inspection system |
| FR2870335B1 (en) * | 2004-05-12 | 2006-07-28 | Snecma Moteurs Sa | THREE-DIMENSIONAL MACHINE WITH SIMULTANEOUS MEASUREMENTS |
| US20060271420A1 (en) * | 2005-05-27 | 2006-11-30 | Peter Anselmann | System and method for performing capacity checks and resource scheduling within a supply chain management system |
| US7784183B2 (en) * | 2005-06-09 | 2010-08-31 | General Electric Company | System and method for adjusting performance of manufacturing operations or steps |
| US20070050172A1 (en) * | 2005-09-01 | 2007-03-01 | General Electric Company | Method and apparatus for measuring throat areas of gas turbine engine nozzle assemblies |
| US7310588B2 (en) | 2005-10-24 | 2007-12-18 | United Technologies Corporation | System and method for verifying the dimensions of airfoils |
| GB0605796D0 (en) * | 2006-03-23 | 2006-05-03 | Renishaw Plc | Apparatus and method of measuring workpieces |
| GB2451697A (en) * | 2007-08-10 | 2009-02-11 | Sigmala Ltd | Adjustable slitting knife holder |
| DE102008016025A1 (en) * | 2008-03-28 | 2009-10-01 | Mtu Aero Engines Gmbh | Method and measuring system for characterizing a deviation of an actual dimension of a component from a nominal dimension of the component |
| DE102008016026A1 (en) * | 2008-03-28 | 2009-10-01 | Mtu Aero Engines Gmbh | Method and device for measuring at least one bore in at least one first surface of a component |
| ES2393871B1 (en) * | 2010-10-26 | 2013-11-06 | Airbus Operations, S.L. | METHOD OF DIMENSIONAL INSPECTION OF A COMPOSITE MATERIAL PART. |
| EP2636857A1 (en) * | 2012-03-07 | 2013-09-11 | Siemens Aktiengesellschaft | A system for testing vanes of a turbomachine |
| US8720526B1 (en) * | 2012-11-13 | 2014-05-13 | Siemens Energy, Inc. | Process for forming a long gas turbine engine blade having a main wall with a thin portion near a tip |
| EP2969294B1 (en) * | 2013-03-11 | 2019-04-24 | United Technologies Corporation | Method of forming a structural guide vane |
| CN103676777B (en) * | 2013-11-19 | 2016-09-28 | 哈尔滨汽轮机厂有限责任公司 | A kind of method utilizing tool setting gauge detection gas passageway of blade of steam turbine surplus |
| EP2998063B1 (en) * | 2014-09-16 | 2019-03-13 | Ansaldo Energia Switzerland AG | Tool for measuring geometrical parameters of a blade or vane in a turbomachine |
| GB201418349D0 (en) * | 2014-10-16 | 2014-12-03 | Rolls Royce Plc | Virtual component alignment |
| US10500678B2 (en) * | 2016-10-06 | 2019-12-10 | Xiamen University | Method for producing drilled cooling holes in a gas turbine engine component |
| SG10201608757PA (en) | 2016-10-19 | 2018-05-30 | Component Aerospace Singapore Pte Ltd | Method and apparatus for facilitating part verification |
| US12037918B2 (en) | 2022-04-05 | 2024-07-16 | Rtx Corporation | Systems and methods for parameterization of inspected bladed rotor analysis |
| US11860060B2 (en) | 2022-04-05 | 2024-01-02 | Rtx Corporation | Integrally bladed rotor analysis and repair systems and methods |
Family Cites Families (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3164909A (en) * | 1959-01-14 | 1965-01-12 | Gen Electric | Automatic gauging system |
| US3839800A (en) * | 1968-08-29 | 1974-10-08 | Ibm | Method and apparatus for precisely contouring a work-piece imprecisely positioned on a fixture |
| US3698138A (en) * | 1969-08-13 | 1972-10-17 | Toyoda Machine Works Ltd | Grinding machine with adaptive control system |
| US3627997A (en) * | 1969-11-13 | 1971-12-14 | Trw Inc | Turbine vane prediction and classification gage and gaging method |
| US3832784A (en) * | 1970-04-30 | 1974-09-03 | Trw Inc | Turbine vane prediction and classification gage and gaging method |
| GB1355999A (en) * | 1970-09-30 | 1974-06-12 | Olivetti & Co Spa | Dimension comparator for machine tools |
| US4053989A (en) * | 1974-04-30 | 1977-10-18 | Mitsubishi Jukogyo Kabushiki Kaisha | Co-ordinates measuring apparatus for an exclusive propeller processing machine |
| US4156835A (en) * | 1974-05-29 | 1979-05-29 | Massachusetts Institute Of Technology | Servo-controlled mobility device |
| US4001069A (en) * | 1974-10-21 | 1977-01-04 | Dynell Electronics Corporation | Arrangement for generating and constructing three-dimensional surfaces and bodies |
| US4128481A (en) * | 1975-02-07 | 1978-12-05 | Erwin Sick Gmbh Optik-Elektronik | Curve following device |
| US4181958A (en) * | 1978-04-21 | 1980-01-01 | The Valeron Corporation | Multiple probe gage system |
| EP0025724A1 (en) * | 1979-08-31 | 1981-03-25 | The Bendix Corporation | Method of making measurements on an object by means of a movable probe |
| US4470709A (en) * | 1980-03-04 | 1984-09-11 | Ford Aerospace & Communications Corporation | Cylindrical tapered sleeve optimized for weight and heat conduction |
| JPS5745407A (en) * | 1980-09-02 | 1982-03-15 | Kosaka Kenkyusho:Kk | Three dimensional coordinate measuring device |
| US4365301A (en) * | 1980-09-12 | 1982-12-21 | The United States Of America As Represented By The United States Department Of Energy | Positional reference system for ultraprecision machining |
| IT1144709B (en) * | 1981-05-15 | 1986-10-29 | Dea Spa | DIMENSIONAL MEASUREMENT SYSTEM SERVED BY A MULTIPLE OF OPERATING ARMS AND CONTROLLED BY A CALCULATOR SYSTEM |
| US4428055A (en) * | 1981-08-18 | 1984-01-24 | General Electric Company | Tool touch probe system and method of precision machining |
| US4470122A (en) * | 1981-09-30 | 1984-09-04 | The Boeing Company | Integrated electro-optical position sensing, workpiece probing and display method and apparatus |
| FR2514530B1 (en) * | 1981-10-09 | 1987-06-19 | Lemoine Cie Ets | METHOD FOR INPUT OF REPRESENTATIVE DATA OF THE FORM OF AN OBJECT |
| CH655270A5 (en) * | 1982-03-15 | 1986-04-15 | Maag Zahnraeder & Maschinen Ag | MEASURING ARRANGEMENT OF A MULTI-AXIS MEASURING SYSTEM. |
| FR2542238A1 (en) * | 1983-03-07 | 1984-09-14 | Sfermi | Method and device for inspecting and treating a metal surface remotely |
| US4612622A (en) * | 1983-07-12 | 1986-09-16 | United Technologies Corporation | Probe for coordinate measuring machine |
| GB2148007B (en) * | 1983-10-01 | 1988-02-10 | Rolls Royce Motor Cars | Profile checking apparatus |
| US4629378A (en) * | 1984-08-27 | 1986-12-16 | Parsons John T | Meltable matrix chucking machining center and process using |
| GB2167862B (en) * | 1984-12-01 | 1989-01-18 | Sigma Ltd | Component inspection apparatus |
| GB8508390D0 (en) * | 1985-03-30 | 1985-05-09 | Ae Plc | Measurement & machining engineering components |
| US4719578A (en) * | 1985-12-09 | 1988-01-12 | Mitsubishi Jukogyo Kabushiki Kaisha | Profiling control apparatus and control method thereof |
-
1985
- 1985-03-30 GB GB858508391A patent/GB8508391D0/en active Pending
-
1986
- 1986-03-18 EP EP86103659A patent/EP0199961B1/en not_active Expired - Lifetime
- 1986-03-18 DE DE8686103659T patent/DE3685362D1/en not_active Expired - Fee Related
- 1986-03-19 US US06/841,511 patent/US4811253A/en not_active Expired - Fee Related
- 1986-03-20 CA CA000504566A patent/CA1269741A/en not_active Expired - Fee Related
- 1986-03-28 JP JP61068874A patent/JPS61226605A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| US4811253A (en) | 1989-03-07 |
| EP0199961A3 (en) | 1989-02-08 |
| EP0199961B1 (en) | 1992-05-20 |
| JPS61226605A (en) | 1986-10-08 |
| GB8508391D0 (en) | 1985-05-09 |
| EP0199961A2 (en) | 1986-11-05 |
| DE3685362D1 (en) | 1992-06-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1269741A (en) | Measurement of engineering components | |
| CA1269742A (en) | Measurement and machining of engineering components | |
| EP0275428B1 (en) | Method for calibrating a coordinate measuring machine and the like | |
| US4945501A (en) | Method for determining position within the measuring volume of a coordinate measuring machine and the like and system therefor | |
| US6941192B2 (en) | Robot machining tool position and orientation calibration | |
| EP0431572B1 (en) | Numerical control device for a machine tool | |
| CA2079334C (en) | Multi-functional measurement system | |
| EP1139189B1 (en) | Process for qualifying accuracy of a NC system | |
| US4815006A (en) | Method and device for calibrating a sensor on an industrial robot | |
| KR101200961B1 (en) | Parallel kinematic machine, calibration method of parallel kinematic machine, and calibration program product | |
| EP0329635A2 (en) | Method for determining positional errors and for compensating for such errors, and apparatus for carrying out the method | |
| EP2208572A1 (en) | Method and device for preparing error map and numerically controlled machine tool having error map preparation function | |
| EP0042960A1 (en) | Method and apparatus for calibrating a robot | |
| EP0279926B1 (en) | Method for determining position within the measuring volume of a coordinate measuring machine and the like and system therefor | |
| US4796195A (en) | Method for machining with improved accuracy | |
| CN111006706B (en) | Rotating shaft calibration method based on line laser vision sensor | |
| CN1250934C (en) | Flexible testing tool detection method for dimensional error of mechanical products | |
| EP0313775B1 (en) | Contactless measuring system for accuracy parameters, especially for industrial robots | |
| Mooring et al. | Calibration procedure for an industrial robot | |
| JPH0728514A (en) | Machine error deriving method | |
| WO2024161242A1 (en) | Calibration method for robotic equipment and system implementing the method | |
| JPH02109662A (en) | Correction of detection error of tracer head | |
| JPH0754445B2 (en) | Robot geometric error correction method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |